Generally, closure devices such as screw-threaded caps of containers with screw-threaded openings such as a neck can be removed relatively easily by unscrewing. This can be dangerous when the container houses drugs, dangerous chemicals and the like and a child, for example, unscrews the closure device and gains access to the contents and then takes the contents with possibly harmful or even fatal results.
Closure devices which seek to provide for safer or authorized opening of the container have been proposed, but they are generally complex and expensive.